1. Field of the Invention
A seal ring for improving the performance of a gear pump, primarily for vehicle transmissions, comprises the milling of a circular ring on at least one lateral face of an inner gear and an outer gear in a gear pump and inserting a friction reducing ring within the milled circular ring. The addition of this ring, especially on remanufactured gear pumps, will reduce the amount of transmission fluid leaking between the gears and the gear pump housing and also reduce the friction between the gears and the gear housing, thus providing more fluid to the transmission and also increasing the pressure while decreasing the amount of heat of the transmission fluid being circulated through the gear pump.
2. Description of Prior Art
An automatic transmission in an automobile allows the engine to operate within a narrow range of speeds while providing a wide range of travel speeds. The transmission serves to provide several gears, allowing the automobile to accelerate while maintaining the engine within its confined limits of operation. When observing the automatic transmission, the basic assortment of components include a planetary gearset, having a sun gear, planet gears, their carrier and a ring gear, a set of bands to lock the gearset, a set of wet-plate clutches to lock other parts of the gear set, a hydraulic system to control the clutches and bands, and a gear pump to circulate the transmission fluid within the transmission.
Essentially, this gear pump is located in the cover or housing of the transmission and has a housing within which an inner gear and an outer gear are seated. The gear pump draws fluid from a sump in the bottom of the transmission and feeds it to the hydraulic system, the transmission cooler and the torque converter. The inner gear of the pump is placed concentrically within the outer gear, with the inner gear hooking up to the housing of the torque converter, and spinning at the speed of the engine, while the outer gear, driven and turned by the inner gear, rotates, drawing the fluid up from the sump on one side and forcing the fluid to the other side to the hydraulic system. The operation of the gear pump is know in the prior art, as indicated in the disclosed literature entitled “How Automatic Transmissions Work”, which is an online basic tutorial guide.
Over time, the gear pump housing and the inner and outer gears often wear due to heat and friction of the rotating inner and outer gears, creating a loss of torque converter pressure, measured by a dynamometer, and transmission cooler flow, causing the transmission to run too hot and eventually burn up, requiring a complete transmission replacement. This occurs more often in poorly maintained vehicles, where the transmission filter is never changed, where the fluid is not replaced when old and burned, or when a transmission is used beyond its intended use, as when towing too heavy a load occurs in an over-drive gear.
The addition of the disclosed seal rings, within the milled circular grooves in the inner and outer gears, restores and improves the operation of the gear pump and thus reduces the cost of repair and increases the efficiency of the transmission pump resulting in a greatly improved operation of the transmission as indicated by greater dynamometer testing and result.
In a review of the prior art, no disclosure was made to an inner and outer gear within a gear pump of an automatic transmission including a circular groove milled into at least one lateral face of each inner gear and outer gear, with a friction resisting ring placed within each respective circular groove, the friction resisting rings serving to reduce friction to the lateral surfaces of the gears and also to seal the contact between the gears and the housing to prevent loss of fluid between the pump housing and the gears, forcing the fluid flow through the gear pump instead of around it.
Other than the prior art indicated in the drawings, U.S. Pat. No. 6,158,997 to Post discloses a gear pump comprising a housing having an inlet and an outlet, a first and second gear having outer perimeter teeth engaging each other laterally, one gear being the drive gear and the other being the pump gear. It is not disclosed as having adaptation to a transmission of an automobile. U.S. Pat. No. 5,161,961 to Zheng, depicts a gear pump in the configuration of the planetary gear arrangement found in a transmission, but not in the adaptive gear pump of the present invention application. The Zheng patent does have radial sealing blocks included within its gear mechanisms, but these sealing blocks are fitted against the tooth tops on the gears, not the lateral faces of an inner gear and an outer gear, and are not friction resisting rings within circular grooves in the lateral faces of the inner and outer gears of the gear pump.